The following U.S. patents describe screens and other apparatus employed in the recycling of drain water: Nos. 4,162,218; 3,440,669; 3,318,449; 4,115,879; 3,112,497; 3,843,976; 3,945,327; 3,884,940; 3,594,825; 4,070,714; 4,009,104; 3,922,730; 4,083,067; and 4,017,395.
These prior patents do not describe nor suggest the effectiveness of the improved structure devised by the applicant for the conservation of water and the conservation of energy required to supply water for waste activities such as toilet use by the recycling of domestic drain water.